Orthodontic treatment is a specialty of dentistry that focuses on the treatment of dental displacement and mal-alignment or misalignment of teeth. Comprehensive orthodontic treatment most commonly involves the use of metal wires that are inserted into orthodontic brackets, which can be made from stainless steel or ceramic materials. The metal wires interact with the brackets to exert continual force on the teeth to gradually urge the teeth toward their intended positions.
More recently, alternatives to conventional orthodontic treatment with traditional braces have become available. For example, systems including a series of preformed appliances/aligners have become commercially available from Align Technology, Inc., San Jose, Calif., under the trade name Invisalign® System. The Invisalign® System is described in numerous patents and patent applications including, for example in U.S. Pat. Nos. 6,450,807, and 5,975,893, as well as on the company's website, which is accessible on the World Wide Web (see, e.g., the url invisalign.com”). The Invisalign® System includes designing and/or fabricating multiple, and sometimes all, of the aligners to be worn by the patient before the aligners are administered to the patient and used to reposition the teeth (e.g., at the outset of treatment). Often, designing and planning a customized treatment for a patient makes use of computer-based 3-dimensional planning/design tools, such as Treat™ software from Align Technology, Inc. The design of the aligners relies on computer modeling of the patient's teeth in a series of planned successive tooth arrangements, and the individual aligners are designed to be worn over the teeth, such that each aligner exerts force on the tooth and elastically repositions the teeth to each of the planned tooth arrangements.
Another orthodontic option is disclosed in U.S. patent application Ser. No. 13/470,681 to Li et al., also assigned to Align Technology. Disclosed is multilayer orthodontic positioning appliance which includes a removable orthodontic tooth positioning appliance having teeth receiving cavities shaped to directly receive at least some of the patient's teeth and apply a resilient positioning force to the patient's teeth. The multilayer appliances can include a hard polymer layer disposed between two soft polymer layers. The orthodontic treatment provides improved material performance, stress relaxation properties and a longer working range.
An alternative orthodontic technology is the LingualWirelign® and Wirelign® technique of Benjamin A. Cassalia, Chalfont, Pa., which provides a system to correct mal-alignment of teeth using wires alone (that is, without orthodontic brackets) for increased patient comfort and a look without visible “braces” or wires on the facial surface of the patient's teeth. The Wirelign® technique uses straight segments of super-elastic metal wire, usually nickel titanium wire, adhered to surfaces of teeth—usually the lingual surface (i.e. the inside surfaces of teeth, as opposed to the front, facial surfaces)—to align teeth.
In certain cases after the use of currently available orthodontic methods for correcting misaligned teeth, the alignment of teeth is improved but the proper arch form may not be obtained. For example, sometimes as teeth are pulled or pushed into alignment, undesirable tooth movements may occur, resulting in an improper arch form. One reason for certain undesirable tooth movements is that wires typically are bonded to each tooth individually at a fixed distance apart and do not permit the teeth to move closer to one another as they are pushed and/or pulled into alignment. In some cases, mal-alignment of teeth may be minor or of a type that is not easily corrected by current orthodontic procedures alone. And in some cases, continued treatment is desired to maintain or improve proper arch form.
Therefore, there is a need in the art for an orthodontic wire alignment system and method that provides improved arch form and continued alignment of teeth when used alone or after use of other orthodontic techniques, that does so in an aesthetically and cosmetically pleasing way, and is comfortable to the wearer (referred to interchangeably herein as the “patient”). The present invention provides an orthodontic system and method that is a comfortable, cosmetically pleasing means of maintaining or improving optimal arch form when used alone or after use of other orthodontic procedures.
The orthodontic system and method of the invention provide a number of advantages over previously available systems and methods. The placement of the coated wire directly to the surface of the tooth and the placement of flowable bonding material over the wire create a low profile smooth surface system compared to typical orthodontic systems that use brackets with increased profile and distance of the wire from the tooth. The smooth surface of the bonding material used in the invention compared to other brackets system with extended wings or doors minimizes irritation and discomfort to the surrounding oral tissues. The present system and method increase the effectiveness of tooth movement as a result of the close proximity of the wire to the tooth and the potential formation of an orthodontic tube along the entire surface of the tooth. These two factors provide and increase engagement of the tooth surface and therefore enable more effective tooth movement, and especially rotational movement of a tooth.
The present system also provides reduced speech related problems as compared to the prior art. The reduced profile and resulting smooth surface of the material used in the invention is comparable to already used fixed lingual retainer systems which have little to no effect of tongue manipulation and speech related problems. Furthermore, because the orthodontic system of the invention is placed preferably on the lingual surface of the teeth and has low profile characteristics, the orthodontic system of the invention is essentially completely concealed or undetected by observers. A further advantage of the system of the invention is its ease of application. The delivery system of the orthodontic system of the invention is designed for easy clinical application of the coated wire and, as such, also provides improved isolation from contaminants from the oral environment of the mouth.
One object of this invention is to improve the arch form obtained after alignment of the teeth using known orthodontic techniques. By “arch” form as used herein is meant the arch derived by the alveolar process on the jaw containing the dental anatomy of the teeth. The invention also may be used alone to correct mal-alignment of teeth if minimal to moderate tooth movement is required. The design of the arch wire system of the invention allows for the continuation of treatment for misaligned teeth using wires alone (that is, without bulky brackets or fixtures) for increased patient comfort. The wire is preferably affixed to the lingual surface of teeth such that it is not visible when the wearer smiles, thus providing a cosmetic benefit as compared to traditional orthodontic appliances or retainers. Also within the scope of the invention is use of the system of on the facial surface of teeth, albeit such use provides a lesser cosmetic advantage than use on the lingual surface of the teeth. The term “facial” herein is used to mean “non-lingual”, as in the non-lingual surface of a tooth or teeth, and therefore includes “labial” and “buccal”, as in the labial or buccal surface of a tooth or teeth.